The present invention relates to a novel elasticated fastener laminate for use in disposable absorbent articles and the like.
Disposable absorbent articles often use tab fasteners that are provided with elastic to allow for adjustment in the fit and a more secure and snug fit. For example, U.S. Pat. No. 3,800,796 (Jacob) teaches disposable diapers with elastic tabs wherein the tabs have an elastic segment between two inelastic segments. One of the inelastic segments is used to attach the tab to the diaper and the other inelastic segment has a PSA to allow the tab to close the diaper. The tab can be made such that the entire tab is formed of an elastic material and the two terminal segments are rendered inelastic, for example by laminating an inelastic material to the end segments. In Jacob, the elastic would be exposed to the adhesive if a tab precursor laminate were directly wound into a roll. This is problematic in that elastics generally can become permanently bonded to or contaminated by adhesives. This construction does not protect the elastic from direct contact with the adhesive. Further, the tabs vary in thickness which would inhibit the formation of a stable roll of the precursor tab fasteners laminate.
U.S. Pat. No. 4,522,853 (Szonn) also discloses an elastic tab adhesive closure for disposable diapers. The tabs disclosed in this patent have an intermediate (middle) elastic piece and adhesive coated end portions. The tab disclosed and claimed is complex and includes multiple additional elements. Szonn again does not protect its elastic from direct contact with adhesive layers. The constructions disclosed in Szonn are complicated and have multiple different layers that would result in considerable variation in the tab thickness making stable roll formation difficult.
U.S. Pat. No. 4,643,729 (Laplanche) also discloses a complex elastic fastener for disposable diapers that comprises three parts. These are, a first lateral side part (inelastic, for attaching to the diaper during manufacturing), a second lateral side part (inelastic, containing PSA for closing the diaper), and an elastic central part. The two lateral parts are parts of a single piece composed of a support band provided with a transverse precut line, which are separated at the time of use (along the pre-cut line). The two lateral parts are bonded to the central elastic part with adhesive bands and the lateral parts also have adhesive on the face opposite the elastic part for bonding to the diaper (one end for manufacturers bond the other end for closing the diaper in use). The elastic tabs taught in Laplanche again would not protect its elastic material from adhesive contact when wound in a roll.
U.S. Pat. No. 4,778,701 (Pape) discloses a roll of laminated strips from which separate elastic closure tabs can be cut. This is a pre-laminated elastic tab closure with a central elastic portion and inelastic end portions, one for attaching to the diaper during manufacturing and one for the consumer to use to close the diaper. The elastic in Pape is also not protected from exposure to the adhesive without an extra piece of protective material. The thickness of this material would also vary significantly over the width of the tab which is undesirable.
U.S. Pat. No. 4,795,456 (Borgers) discloses an extensible tab for disposable diapers that is stabilized (inextensible) until the user deploys the tab for diapering. This inextensibility of the elastic central segment is achieved by the tab construction including a non-extensible web (e.g. a release tape or liner) that bridges the inextensible end segments (as does the elastic segment) until the tab is opened for use. In Borgers, the elastic is again not protected from the adhesive. Also, the construction requires multiple adhesive layers and film layers such that it would be costly and difficult to manufacture.
U.S. Pat. No. 4,834,820 (Kondo) discloses an elastic diaper closure tab containing an elastic sheet and an inelastic retaining sheet which is directly bonded to the elastic sheet in the terminal end regions and the inelastic sheet has a cut-off groove in the center portion. When using the diaper the consumer manually rips apart the retaining sheet along the cut-off groove, whereupon the center of the elastic sheet is made flexible (elastic) as the retaining sheet no longer bridges the elastic sheet between the areas where the retaining sheet and the elastic sheet are bonded. The tab further has adhesive on the underside of the elastic sheet to anchor the tab to the side of the diaper (manufacturers bond) and to be used for closing the diaper. The structures (elastic tabs) taught in Kondo again require multiple layers of adhesive and fails to protect the elastic from direct contact with the adhesive layers if wound into a roll.
U.S. Pat. No. 5,057,097 (Gesp) discloses elastic diaper tape tabs wherein there is adhesive on the end segments and a central segment free of adhesive, and wherein the tape backing is a multilayer elastic film (e.g. a co-extruded elastic with inelastic skin layers). In Gesp, the elastic is protected from direct exposure to the adhesive layers but the terminal portions are not necessarily inelastic as the entire tab is generally elastic which could result in the tab failing during use. Also, the elastic is always exposed prior to use.
HEI 4[1992]-17059 (Sho 59[1984]-67022/Kokei No. Sho 60-215803, Hida) discloses a tab for disposable diapers having non-extensible end regions and an extensible sheet that connects the end regions and in which at least one part of the overlapping area of the end members and the extensible sheet are non-bonded. Again, the elastic in this construction is not protected from contact with the adhesive if wound into a roll form and a complicated multiple step construction process is required.
There is a need for a tab construction utilizing an elastic central region where the terminal ends are inelastic, which tab is easy to manufacture and provide in a stable roll form and where the elastic is simultaneous securely attached to the inelastic region and protected from direct contact with adhesive if wound into a roll while providing excellent aesthetic features.